HARTFORD -- The state last year gave up $63 million in interest and penalties to garner $193 million in back taxes, a noteworthy feat helped by a one-time amnesty program to induce deadbeat taxpayers to pay up. Now the state is looking for $75 million more in back taxes -- and many are wondering if officials can pull it off without the carrot of amnesty.

The money is crucial to balancing the $19 billion budget adopted last weekend by the Legislature's majority Democrats after $500 million in surplus funds evaporated. The new budget relies on $200 million in "fund sweeps," or budget transfers, unspecified savings and the "last-minute discovery" of $75 million in "miscellaneous" tax receipts.

Those tax receipts are part of a developing plan by the state Department of Revenue Services to arm-twist the state's remaining delinquent taxpayers to fork over some of the $300 million in back levies owed.

Asked if his agency was put on the firing line, DRS Commissioner Kevin Sullivan on Tuesday said he would have preferred more time to collect the money -- DRS has until July 2015 to obtain the funds -- but that tax collectors are ready.

"This is our initiative," Sullivan said. "We wanted a little more prep time since amnesty closed. But there is thinking behind this. It's not a gimmick. We would not have given the green light for that number if we didn't think we could get it."

Republicans slammed the budget developed under the leadership of Gov. Dannel P. Malloy and pointed to the $75 million in anticipated receipts as one of its most glaring shortcomings.

"This budget is structurally unbalanced, full of gimmicks and further increases (in) taxes and spending," said Senate Minority Leader John McKinney, R- Fairfield.

Sullivan said the plan to collect back taxes is sound and pointed out that most of the remaining delinquent taxpayers are businesses, not small taxpayers or individuals.

"The rest were not eligible for amnesty or could not make one single payment. But we could enter into settlements," he said.

DRS is ramping up cooperation between state agencies so back taxes are paid before licenses, such as those issued to car dealers, are issued, or payments, like Medicare reimbursement, are distributed, Sullivan said. Other steps include cracking down on companies that do business in multiple states.

"They structure income to avoid paying tax liability in Connecticut," Sullivan said. "It's a big issue around the country. We have a contract for outside services, and this will give us authority to probe that."

Still, in a letter to lawmakers delivered over the weekend, Alan Calandro, director of the nonpartisan state Office of Fiscal Analysis, said he could not confirm that $75 million could be collected before the 2015 fiscal year ends.

"In the absence of information to support the estimate, we are not able to verify or develop our own estimate," Calandro wrote. But he added, "it is not impossible" to obtain $75 million in back taxes "through some range of new mechanisms not previously available."